McMaster filters are only about $4 each and you get the exact rating. Shipping is $4 for up to a dozen.

Panyhose, jeans, sheets, etc are OK for pre-filtering, but they stretch and are not consistent.

You can also buy 200 micron bucket or barrel filters - I see them on Ebay. They are hard plasic and just fit over the top.

Do not scrimp in filtering! I have 11,000 miles on my 300SD filters running on UCO (WVO). Everything goes through a 10-micron Goldenrod before it goes in the car.

__________________
1984 300Sd 210k

Former cars:
1984 300D 445k (!!) (Strider) Original (and not rebuilt) engine and transmission. Currently running on V80 ( 80% vegetable oil, 20% petroleum products). Actually not, taking a WVO break.
1993 300d 2.5 275k. Current 120/day commuter
1981 300SD 188k (Hans) Killed by a deer